How to convert this Date string into a long?

Question

I am having issues converting a String that has this format for date from the server into a long?

Example Date String - "2016-07-04T00:02:34.457Z" (Note this is a string)

I tried this below but needs try catch around gmt, when I add it and a not null around cmtDt - then I initialize cmtDt to 0 pre setting it on the bottom and it is always 0.

Calendar c = Calendar.getInstance();
TimeZone tz = c.getTimeZone();
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ssZ");
formatter.setTimeZone(tz);
Date gmt = formatter.parse(comment.getDateCommented());
cmtDt = gmt.getTime();

score 3 · Answer 1 · answered Aug 11 '16 at 03:42

3

First, your input String includes milliseconds (and your format does not). Second, your input String includes a literal Z (which is presumably to indicate a UTC timezone). Finally, getting your system timezone and assigning it to the formatter isn't reliably going to be UTC. You need something like,

SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ss.SSS'Z'");
formatter.setTimeZone(TimeZone.getTimeZone("UTC"));
try {
    Date gmt = formatter.parse("2016-07-04T00:02:34.457Z");
    long cmtDt = gmt.getTime();
    System.out.println(cmtDt);
} catch (Exception e) {
    e.printStackTrace();
}

Which I ran, and got

1467590554457

answered Aug 11 '16 at 03:42

Elliott Frisch

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I tried this code, getting a 0 now, @Jason's code above worked just not the timezone aspect – Lion789 Aug 11 '16 at 03:45
@Lion789 Note that my code (if you copied and pasted then tsk-tsk) makes `cmtDt` local to the try block (and thus it would shadow any other `cmtDt` you have). Finally, try a debugger. – Elliott Frisch Aug 11 '16 at 03:47
Local? I have cmtDt set outside of it if that should not work then? – Lion789 Aug 11 '16 at 03:50
And my code has `long cmtDt = gmt.getTime();`, which is another variable named `cmtDt`. Edit your post into a [MCVE](http://stackoverflow.com/help/mcve). – Elliott Frisch Aug 11 '16 at 03:51
However thank you I have combined your timezone method with the Formatting @jason provided and it works now! – Lion789 Aug 11 '16 at 03:51

score 1 · Answer 2 · answered Aug 11 '16 at 03:37

1

Your format string for the SimpleDateFormat needs to be:

SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ss.SSS");

My test code that works is:

Calendar c = Calendar.getInstance();
TimeZone tz = c.getTimeZone();
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ss.SSS");
formatter.setTimeZone(tz);
Date gmt = formatter.parse("2016-07-04T00:02:34.457Z");
long cmtDt = gmt.getTime();
System.out.println("cmtDt = " + cmtDt);

answered Aug 11 '16 at 03:37

Jason

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Timezone does not seem to work, trying to have it locally affect and it is showing a future date... am I adding that wrong then – Lion789 Aug 11 '16 at 03:40

score 0 · Answer 3 · answered Aug 11 '16 at 03:41

The format in SDF needs to be fixed. The following will help you.

    Calendar c = Calendar.getInstance();
    TimeZone tz = c.getTimeZone();
    SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSX");
    formatter.setTimeZone(tz);
    Date gmt = formatter.parse("2016-07-04T00:02:34.457Z");
    long cmtDt = gmt.getTime();
    System.out.println(cmtDt);

Prints : 1467599640457

How to convert this Date string into a long?

3 Answers3